Greeting cards and children's books often include pop-up displays. Examples are sliding cut-outs with edge-operated tabs that cause the cut-out figures move on a page, and stand-up displays that arise when pages are unfolded.
U.S. Pat. No. 1,658,968 to Carroll shows a display device with three layers. The inner layer moves within an envelope formed by the outer layers. A slide member of the inner layer protrudes from the envelope; when it is pulled, the display changes by relative sliding of panels of the back and inner layers. There is no folding, and no pop-up feature.
U.S. Pat. No. 1,008,195 to Pritchard shows a hollow postcard from which an inner card may be pulled. The inner card has longitudinal cuts and creases that allow an inner portion to be folded up. The creases do not appear to interact with the envelope.
Warenback's U.S. Pat. No. 4,062,138 shows a pedestal display device made from a blank of cardboard with a die-cut inner display portion. The display portion is pulled loose and the surrounding part folded to form a base to support the display portion. No pop-up feature is disclosed.
Moran, in U.S. Pat. No. 5,010,669, shows a partially die-cut postcard that folds into a display and stand. It is similar to Warenback. U.S. Pat. No. 4,161,833 to Wagner shows a stand-up display board and base die-cut from the same blank.
U.S. Pat. No. 3,090,144 to Malamude discloses a pop-up display for greeting cards, store advertisements, etc. The pop-up action is performed by a rectangular paper box glued into the card. The box has ends adapted to allow it to collapse into a plane when the card is closed and lie between two sheets; when the card is opened the device forms a rectangular corner step between the two opened sides of the card. The display appears by unfolding (changing the angle at a fold) only and not by pulling a slide member (sliding one part over another). Malamude also shows stacked folded pop-ups.
U.S. Pat. No. 5,259,133 to Burtch discloses a pop-up card and a blank for making the card. The device includes a base sheet 12, a cover sheet 20, and an actuator (slide) member 16. A tab end 14 of the slide member protrudes from between the cover and the base, which have mating indentations to provide a grasping point on the slide member. The end of the slide member distal from the pull tab is glued to a die-cut and creased portion of the cover. When the tab is grasped and pulled, that portion of the cover folds into a tent-like shape. The Burtch card is formed by folding a blank along fold lines that run parallel to the slide member, as shown in FIGS. 2-5 of the Burtch '133 patent. When the card is assembled and the pop-up display is worked, the slide member moves in a direction parallel to the assembly fold lines.
The Burtch design has the disadvantage that portions of the blank, such as strip 42 portion and pull tab portion 32, must be separated from the blank and then glued back on. Each such piece requires separate alignment. Another disadvantage is that the folds are not spaced at regular intervals, which complicates automatic assembly. As seen in Burtch FIG. 2, the distance from fold line 34 to fold line 38 is much greater than the distance from fold line 34 to the edge at 48, which is the end of the left-most fold section after the slide member 32 is cut away. The difference in distance means that if the Burtch device is made by folding equipment, the equipment must alternately make folds at two different distances from edges, complicating the manufacture thereof.
Cards related to the Burtch '133 disclosure include a type of circular cardboard baseball card (one such card bears the indicia "Innovative Promotions Int'l Ltd. Patent No. 5259133" and "Printed in Canada"). This card is made from a circular base; a slide member having the shape of a similar circle but with chords removed to leave parallel sides equidistant from the center of the circle; a circular cover with parallel cuts; and two shims having the shape of the chords missing from the slide member, lying between the cover and base. The base, shims, and cover are glued together to form a sandwich. The slide member end distal the pull tab is glued to the cover, and the cover is creased in between its two ends. When the tab is pulled, the cover folds about the crease line and pops up.
The cover is die-cut around a figure, the head and torso of a baseball player. The cut extends between two ends of the crease. The cut-out figure extends outward when the display pops up, as taught by the Burtch patent. There are no folds visible and this card apparently is assembled from five separate pieces: base, cover (20 in Burtch), slide member (16 in Burtch), and two side shims (42 and 44 in Burtch). The great number of pieces which must be independently and stepwise aligned and glued make this card difficult to assemble, whether by hand or by machine.
In Burtch-type cards, the slide member is made wider than the distance between the cuts on the cover so as to retain the slide member edges between the base and the cover. This has the disadvantage that the width of the slit, through which the slide member is worked back and forth to pop up the display, must be as wide as the slide member. The wide opening weakens the structure.
In such Burtch-type cards, shims are needed as guides for the slide member because there is nothing to locate the slide member laterally where it emerges from the envelope formed by the base and cover. Without the shims the slide member could cock (rotate about a line normal to the plane of the card) and jam. Were the cover and base merely glued together without shims there would be no definite edge for the slide member to bear against, and consequently the cover and base would be pried apart by sideways action of the slide member, if the slide member were not pulled straight out each time. The slide member edge would peel the cover from the base and ruin the card. Adhesives are notoriously prone to failure under peeling action.
The prior art does not disclose any pop-up structure that can be made without shims and still withstand normal use, nor does it disclose any means of locating a pull-tab slide member without shims. Also, the prior art does not disclose any pop-up device that does not require assembly of disconnected parts. Further, the prior art also does not show any pop-up card or blank for a pop-up card which is adapted to automatic assembly.